Cardiac sudden death during sports activity was the most important subject in sports medicine. Impaired cardiac function after strenuous exercise, such as an ultramarathon or triathlon, was so called ‘cardiac fatigue'. But, our past study showed impaired cardiac function was occurred by myocardial injury in an ultramarathon. In one of our results, the decrease of left ventricular contractility function was correlated.In this study, levels of plasma atrial natriuretic peptide, brain natriuretic peptide, catecholamines, and cardiac troponin T were determined before and after a 100-km ultramarathon in 10 health men to examine the effects of the strenuous exercise on levels of atrial natriuretic peptide and brain natriuretic peptide and correlations between the natriuretic peptide and cardiac troponin T as a maker for myocardial injury. The levels of natriuretic peptide were strongly correlated with increased in cardiac trponin T level after the ultramarathon race.Myocardial injury could d
… Moreeveloped in some endurance athletes despite the absence of coronary arterial disease and idiopathic myocardial hypertrophy. The two mechanisms were thought as high catecholamines directly suffered cardiac muscle and coronary vasospasm with magnesium deficiency. The cardiac muscle was suffered from high concentration of free fatty acid produced by catecholamine-induced lypolysis. Intra-cellular magnesium ion deficiency and high catecholamine levels may be correlated with vasospastic angina, and the strenuous exercise induced hypomagnecemia and high catecholamine levels. The levels of serum magnesium ion levels and intra-cellular magnesium levels were not decreased before and after a 100km ultramarathon. In healthy runners, serum magnesium and intra-cellular magnesium did not decreased in strenuous exercise. The correlation between serum catecholamin levels and cardiac trponin T level were not significant. The direct catecholamin induced myocardial injury could not be proved in this study.In conclusion, we thought that cardiac sudden death in sports activities was occurred by not only high catecholamin levels but also exercise induced vasospams with magnesium ion insufficiency, multiple factors might be effected on myocardial injury in a strenuous exercise. Less